[ARCHIVE] Migration Theory

Originally published Nov 29, 2018

Toby Fitzpatrick

2021-06-12 2 min read

Migrants and refugees across the globe are currently recipients of a lot of media attention. Public opinion in Europe and the Americas has become extremely polarised. This can be seen most recently in the reaction to the caravans of Honduran migrants travelling through Mexico in search of opportunity in the U.S. Shrouded in fake news of ISIS members joining the caravans (espoused by Fox News and adopted by Trump) and inciting angry protests in the Mexico-U.S border-city of Tijuana, migrants are eliciting a frenzied response from politicians and the public.

Perhaps if we turn to the science of migration, we can overcome some of the visceral reactions – in an attempt to temper the tempers.

According to the World Bank Group’s Report Preparing for internal climate migration, over the last fifty-or-so years scientific literature has adopted three major migration theories. The oldest and historically most prevalent is the classical economic theory of migration that treats individuals as rational actors who move from low-opportunity to high-wage markets. This has recently been eclipsed by the more nuanced 'push-pull' and 'New Economics of Labour Migration' (NELM) theories, as the classical theory lacks key aspects such as the fact that people never have perfect information, or that the poorest people often lack even the financial means to make migratory journeys. The push pull theories identify factors in emigrants’ countries of origin and destination that may ‘push’ or ‘pull’ them to migrate. They also include personal factors; poverty and migration networks might push people from their birthplace; jobs, family and social services may pull them towards a new destination. NELM goes further, realising that decisions aren’t made by individuals alone. Large households may be inclined to send family members away in order to diversify their income sources and reduce the number of mouths to feed.

How does climate change affect this picture?

A burgeoning body of observational evidence from the last five or so years (IPCC 2013) is establishing the extent to which the changing climate will exacerbate migration. The most direct changes in migration patterns stem from the increased frequency and intensity of weather events such as hurricanes. This often forces societies to migrate. Although many attempt to return home, they are often left optionless.

The more insidious aspects of climate change can trigger decisions to migrate. As can be seen in the figure below (courtesy of the World Bank), climate change affects factors on the levels of an individuals’ choice (micro-level) and beyond (macro-level). Here it is important to note that establishing direct causation of climate change is a tricky business. However, mathematical models are used to statistically infer the extent to which climate plays its role in an emigrant's decision.

Looking toward the end of the century, increased temperature, resource scarcity, sea level and extreme weather are all going to increasingly infect the decision-making process of potential emigrants. This will likely pull many more people towards Europe and North America. If popular opinion remains so divided in the future, how are we going to keep our heads?